全文获取类型
收费全文 | 605篇 |
免费 | 8篇 |
国内免费 | 18篇 |
专业分类
安全科学 | 26篇 |
废物处理 | 22篇 |
环保管理 | 150篇 |
综合类 | 60篇 |
基础理论 | 147篇 |
污染及防治 | 164篇 |
评价与监测 | 39篇 |
社会与环境 | 19篇 |
灾害及防治 | 4篇 |
出版年
2023年 | 3篇 |
2021年 | 2篇 |
2020年 | 3篇 |
2019年 | 2篇 |
2018年 | 8篇 |
2017年 | 4篇 |
2016年 | 12篇 |
2015年 | 11篇 |
2014年 | 11篇 |
2013年 | 81篇 |
2012年 | 16篇 |
2011年 | 14篇 |
2010年 | 11篇 |
2009年 | 19篇 |
2008年 | 32篇 |
2007年 | 30篇 |
2006年 | 22篇 |
2005年 | 20篇 |
2004年 | 28篇 |
2003年 | 24篇 |
2002年 | 24篇 |
2001年 | 20篇 |
2000年 | 15篇 |
1999年 | 12篇 |
1998年 | 9篇 |
1997年 | 6篇 |
1996年 | 7篇 |
1995年 | 8篇 |
1994年 | 10篇 |
1993年 | 5篇 |
1992年 | 15篇 |
1991年 | 8篇 |
1990年 | 6篇 |
1989年 | 9篇 |
1988年 | 9篇 |
1987年 | 4篇 |
1986年 | 8篇 |
1985年 | 9篇 |
1984年 | 11篇 |
1983年 | 15篇 |
1982年 | 9篇 |
1981年 | 8篇 |
1980年 | 16篇 |
1979年 | 7篇 |
1978年 | 7篇 |
1977年 | 3篇 |
1976年 | 4篇 |
1975年 | 3篇 |
1974年 | 2篇 |
1966年 | 2篇 |
排序方式: 共有631条查询结果,搜索用时 296 毫秒
51.
Interactions between water and land in The Netherlands 总被引:1,自引:0,他引:1
The Netherlands are one of the most densely populated coastal countries in the world and there is only limited space for living,
working, transport and recreation, while there is also the need to preserve and expand valuable natural habitats. In order
to solve many existing and future conflicts of interest, and in order to create ‘added value’, strategies are developed to
optimize the use of water-land systems.
The principle of ‘building with nature’ is applied in order to integrate land in sea and water in land in such a way that
future generations will be able to use coastal resources in a sustainable way, including a minimal effort to maintain the
coastline and the promotion of a multiple-use system.
The concept of Integrated multifunctional sustainable coastal zone development is introduced. This concept deals with a balanced
approach to the lack of space for present and future coastal uses in relation to each other, to the hinterland, and to the
sea. Flexible master plans are developed, taking into account many functions of the coastal zone, and facilitating adaptation
to future developments—e.g. impacts of climate change and relative sea level rise. In this regard increasing the flexibility
of the coastal zone is of vital importance.
Large-scale coastal land reclamations in The Netherlands are dealt with, based on two different principles: (1) polder systems
(low lying land reclamations surrounded and protected by dikes), (2) systems of ‘building with nature’—land reclamation protected
by man-made foreshores, beaches and dunes. In the latter type new flexible dynamic-equilibrium coasts are created for many
functions, while coastal vulnerability is reduced and a flexible coast is developed. 相似文献
52.
53.
Mathematical Modeling of Column and Field Dense Nonaqueous Phase Liquid Tracer Tests 总被引:2,自引:0,他引:2
David J. Wilson Ronald A. Burt Douglas S. Hodge 《Environmental monitoring and assessment》2000,60(2):181-216
Mathematical models for the simulation of dense nonaqueous phase liquid tracer tests (DTTs) in laboratory columns and in the field are developed and examined. The DTT technique is a means of estimating the quantity of dense nonaqueous phase liquid (DNAPL) in a domain of interest in an aquifer. The two-dimensional field DTT model uses the Method of Principal Directions and an asymmetrical upwind algorithm for describing advective transport. Both models include diffusion transport of tracer into and from low-permeability porous structures such as clay lenses, as well as the mass transport kinetics of partitioning tracer to and from the DNAPL droplets. The dependence of the effluent tracer concentration curves on the parameters of the models is explored, and conclusions are drawn regarding the applicability of, and several possible problems with, the DTT technique. Model results indicate that the DTT performs well at locating distributed droplets of DNAPL, but is unlikely to be useful in the assessment of pooled DNAPL. 相似文献
54.
Marc Niggemann Jens Jetzkowitz Stefan Brunzel Matthias C. Wichmann Ronald Bialozyt 《Ecological modelling》2009,220(9-10):1339-1346
Distribution patterns of plants are affected by human activities such as creation, destruction or modification of habitats. However, another important question is to what extent humans shape plant distributions by acting as dispersal vectors. In order to answer this question we developed a simulation model for the spread of plant species between human settlements. This was done on the basis of extensive sociological and ecological data on a regional scale. With regard to the sociological data, human movement behaviour defined the amount of exchange between the settlements. Gardening types represented the potential habitat in our model. The ecological data was derived from a vegetation survey carried out in 2003, which was a repeat of a survey between 1974 and 1981 along the same transects. From these surveys, we studied the distributions of 13 species in 67 settlements. In our model, the earlier survey provided the data for the initial distribution. The simulated pattern was consequently compared with the distribution pattern in 2003. In the model, dispersal kernels based on patterns of human movement between settlements led to a better match with the distribution patterns than a null model simulating pure distance dependent dispersal for all species. This was statistically significant for seven of the thirteen species. A striking result was that alien species seem to benefit more from human dispersal than native species. We emphasize the importance of the sociological data on human movement behaviour in parameterizing our regional scale model. This study provides quantitative evidence on the impact of human movement behaviour on the distribution of plant species in suburban areas. 相似文献
55.
Ronald R. Swaisgood 《Conservation biology》2009,23(5):1338-1340
56.
Option value is estimated for the Washakie Wilderness, northwest Wyoming, USA, using the contingent valuation technique. Consumer
surplus, the traditional measure of economic value, is estimated separately and compared with option value. Several populations
are tested, including Washakie visitors, Yellowstone National Park visitors, and residents from four metropolitan test markets:
Salt Lake City, Utah; Portland, Oregon; Nashville, Tennessee; and Orlando, Florida, USA. The average annual preservation option
value (consumer surplus) expressed by on-site wilderness visitors is $46.17 ($80.13), by urban residents is $9.70 ($8.97),
and by rural residents is $8.43 ($7.80). Four selected attributes are determined to be important in motivating option demand
for the Washakie, including existence value, bequest value, the desire for an on-site visit, and interest in securing the
visiting privileges of others. The results suggest that option value is important in wilderness valuation and that off-site
users account for a large part of the economic value of wilderness. 相似文献
57.
58.
Park design principles are proposed on the basis of consideration and analysis of rare plant species in Great Smoky Mountains National Park, USA. Rare species richness can be used as a simple measure of preservation success. A semilogartihmic species-area model for the Smokies was used in this analysis. Species richness would increase logarathmically with expansion of the national park area. An analysis of the relationship between species richness and the distribution of geologic and topographic features in the national park was also reported. An asymptotic relation was documented for the accumulation of newly recorded rare and endangered vascular plant species in the Smokies region up to 1978. Several multiple regression linear models predicted rare vascular plant species richness in Great Smoky Mountains National Park from area and topographic variates.Preserve design criteria can be based upon species-area, environmental gradient, and natural features distribution patterns for the specific taxa and biogeographic region under consideration. In addition, natural history characteristics for particular vulnerable species must be assessed. Rather than concentrating on the preservation of undocumented immigration and extinction processes, preserve design should be directed towards protecting geographic components and gradient patterns characteristic of a region. 相似文献
59.
Large-scale constructed wetlands for nutrient removal from stormwater runoff: An everglades restoration project 总被引:14,自引:0,他引:14
Mariano Guardo Larry Fink Thomas D. Fontaine Susan Newman Michael Chimney Ronald Bearzotti Gary Goforth 《Environmental management》1995,19(6):879-889
The South Florida Water Management District (SFWMD) constructed a wetland south of Lake Okeechobee to begin the process of
removing nutrients (especially phosphorus) from agricultural stormwater runoff entering the Everglades. The project, called
the Everglades Nutrient Removal (ENR) project, is a prototype for larger, similarly constructed wetlands that the SFWMD will
build as part of the Everglades restoration program. This innovative project is believed to be one of the largest agricultural
stormwater cleanup projects in the United States, if not in the world. This publication describes the ENR project's design,
construction, and proposed operation, as well as the proposed research program to be implemented over the next few years. 相似文献
60.
Ronald A. Chadderton Robert G. Traver Jayaram N. Rao 《Journal of the American Water Resources Association》1992,28(6):1069-1076
ABSTRACT: This paper presents a study which used a standard, hydraulic computer model to generate detailed design information to support conflict analysis of a water resource use issue. As an extension of previous studies, the conflict analysis in this case included several scenarios for stability analysis - all of which reached the conclusion that compromising, shared access to the water resources available would result in the most benefits to society. This expected equilibrium outcome was found to maximize benefit-cost estimates. 相似文献